This application pertains to the art of non-operative esophageal treatment and more particularly to apparatus for the treatment of esophageal varices and other esophageal disorders by the injection of medications. The invention is particularly applicable to the treatment of esophageal varices in conjunction with the treatment of cirrhosis of the liver and will be described with particular reference thereto. It will be appreciated, however, that the invention has broader applications such as the treatment of esophageal disorders whose healing is promoted by a localized injection of medication.
A common side effect to cirrhosis of the liver is the development of esophageal varices. These varices are varicose venous channels which develop in the esophagus because the blood flow from the intestine to the liver is impaired by the cirrhosis. When one of these varices ruptures, life threatening internal gastrointestinal bleeding occurs. Treatment of the varices in patients with cirrhosis of the liver is hindered by the generally weakened liver condition. Many of these patients doe not have an adequate liver reserve to withstand surgery or the physiological stresses of general anesthesia.
In 1939, a procedure was described for treating the varices by injections. In this procedure, a needle was passed through a rigid endoscope and into a selected varix. Each selected varix was injected with an agent that caused scarring of the internal wall of the vein. This tended to eliminate or reduce the severity of future bleeding episodes. When this procedure was developed, endoscopes consisted of a long, rigid system of lenses housed in a long metal tube. The use of a rigid endoscope usually requires the use of a general anesthesia. This rigid endoscopic procedure was never adopted by the medical profession. Rather, operative approaches to the management of hemorrhages from esophageal varices have become the standard treatment.
Today, flexible, fiberoptic endoscopes are in common usage. The fiberoptic endoscope is a flexible tubular instrument in which light is carried in and out of the patient by bundles of glass fibers. The proximal end of the instrument i.e., the end held by the physician, has a viewing lens and controls for manipulating its opposite or distal end. The controls selectively bend the distal end causing the distal tip to be angulated in any selected direction. This allows the instrument to follow the course of the gastrointestinal tract and examine its walls. The fiberoptic endoscopes, conventionally, have a tubular biopsy channel extending from the proximal end to the distal end. Various accessories are passed through the biopsy channel into the patient's gastrointestinal tract.
It has been suggested that the 1939 injection procedure described above be adapted for use with flexible, fiberoptic endoscopes. Specifically, it has been suggested that a needle be secured to a length of flexible, plastic tubing by tying several ligatures. The flexible tubing and needle are diametrically sized to be received in the biopsy channel of conventional fiberoptic endoscopes. This procedure, however, has many drawbacks. One problem is that the rigid needle, about a centimeter in length, tends to impale the side walls of the biopsy channel. Because this construction is unsuitable for passing the needle from the proximal end to the distal end of the biopsy channel, the needle is commonly backloaded. That is, the tubing is threaded from the distal end backward through the biopsy channel to the proximal end. Another problem has been the needle becoming detached from the tubing during injections. If the needle is lengthened to enable it to be tied more securely to the tubing, the problems associated with moving the needle through the biopsy channel are compounded. Yet another problem has been the difficulty in controlling the depth of the insertion of the needle into the varix. The diameters of the tubing and the needle are so close that the tubing is readily inserted with the needle through the puncture into the varix. This tends to enlarge the puncture and cause excessive damage to the varix.
The present invention overcomes the above-referenced problems and others, yet provides an injector for non-operative treatment of esophageal varices and other esophageal disorders.